Processes have been developed for the manufacture of ABS polyblends having desirable toughness and other physical properties. Such processes have had problems in producing polyblends having a low residual unpolymerized monomer content. In particular, the styrene type monomers are highly soluble in the polyblend and have a high boiling point, hence, are difficult to remove from the finished polyblend. Prior art processes, have used stripping methods in emulsion polymerization or devolatilization methods in mass polymerization which are costly and fail to reduce the residual monomers to a level acceptable for many uses. Hence, it is the objective of the present invention to provide a process wherein residual unpolymerized monomers, particularly the styrene type which polymerize slowly at high conversions, can be readily converted into interpolymers, negating the need for costly stripping and devolatilization steps for removal of the monomer and their subsequent recovery for ecology reasons.
Another objective is to provide a facile and relatively economical process for preparing such rubber-interpolymer polyblends which permits utilization of existing equipment and techniques for preparation of the grafted rubber components thereof.
Other related objectives and advantages will be readily apparent from the following detailed specification.